Detergent and cleansing compositions intended for use as personal cleansing products not only must exhibit cleansing action but they must also be non-irritating or have low irritation potential to the skin and the eyes. The major use for such compositions is in shampoos; but other uses include liquid skin cleansers, baby baths, bubble baths and the like. A suitable composition for use as a shampoo must remove the surface grease and leave the hair and scalp clean. In addition, it should leave the hair lustrous, soft and manageable; still further, it is desirable that it possess good lathering and foaming properties for consumer acceptability.
Synthetic detergents well known in the art include anionic, cationic, amphoteric and nonionic detergents or surfactants, as they are usually referred to. The surfactants generally exhibiting the most superior properties in terms of foaming, cleaning and end result attributes are the anionic detergents. Thus, most shampoo and cleansing formulations contain anionic surfactants as one of the active ingredients. These surfactants, however, have a tendency to be very irritating to the skin and the eyes in the levels normally utilized, i.e., above 10% by weight of the total composition. For this reason, anionic detergent compositions intended for personal use are modified by subsituting a significant amount of nonionic surfactants which are generally mild although of less effective cleansing ability. Certain amphoteric surfactants are reported to have a low eye irritation potential. In an article on "Baby Shampoos" by H. S. Mannheimer, American Perfumer, 76, 36-37 (1961), there is described surface active agents which are complexes of an anionic surface active agent and a particular amphoteric surface active agent which are argued to be non-irritating to the eyes. A number of similar compositions are available commercially and while they are milder than conventional shampoos, they are still found to be somewhat irritating or lacking in some other desired property. Thus, there is still a need for shampoo and other cleansing compositions in which irritancy can be substantially eliminated without sacrificing other desired properties such as cleansing and foaming attributes.
Several U.S. patents describe compositions in which both amphoteric and nonionic surfactants are incorporated in anionic surfactant compositions. Thus, in U.S. Pat. Nos. 2,999,069 and 3,055,836 there are described shampoo compositions comprising certain mixtures of ethoxylated anionic, amphoteric and polyethoxylated nonionic surfactants. Further, in U.S. Pat. No. 3,928,251 there are described shampoo compositions comprising certain mixtures of anionic, nonionic and zwitterionic surfactants. Similarly, in U.S. Pat. No. 3,950,417 shampoo compositions are described for which low ocular irritancy is claimed. In these compositions, nonionic and amphoteric surfactants have been added to modify anionic surfactants. All of these compositions include a nonionic surfactant as an essential component as well as an anionic surfactant and as mentioned above, these surfactants have various negatives.